There is no course that you can to refer to as being marketable in this era in Kenya. It all boils down to your achievements, experience, skills and network. However, if you are looking for a course which you stand a high chance of getting full time employment in Kenya, then the best choice is Education.
It should be noted that TSC takes time to employee fresh graduates but at least you will get somewhere to teach as you wait to be deployed by TSC.
Tip: When looking for a degree programme to do in University or College consider one that can survive the future of work. Jobs like bank teller which used to be in high demand a decade ago are dying out because of automation technology.